Submission #1038326

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038326		otarius	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	852 ms	54908 KiB

joioi

#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#define ff first
#define sc second
#define pb push_back
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define ull unsigned long long
#define all(x) (x).begin(),(x).end()
 
// #define int long long
// #define int unsigned long long
 
// #define ordered_set(T) tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>
// #define ordered_multiset(T) tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>
 
void open_file(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}
 
// const ll mod = 1e9 + 7;
// const ll mod = 998244353;
 
const ll inf = 1e9;
const ll biginf = 9 * 1e18;
const int maxN = 2005;
 
int n, m, mn = inf, arr[maxN][maxN], dp[maxN];
bool check(int mid) {
    bool f = 0;
    int i, j, mx, mn1, mx1;
    for (int f1 = 0; f1 < 2; f1++) {
        for (int f2 = 0; f2 < 2; f2++) {
            mn1 = inf; mx1 = 0;
            for (int _i = 1; _i <= n; _i++) {
                i = _i;
                if (f1) i = n - _i + 1;
                dp[i] = 0; mx = 0;
                for (int _j = 1; _j <= m; _j++) {
                    j = _j;
                    if (f2) j = m - _j + 1;
                    mx = max(mx, arr[i][j]);
                    if (mx - mn > mid) break;
                    dp[i]++;
                } if (!f1) dp[i] = min(dp[i], dp[i - 1]);
                else dp[i] = min(dp[i], dp[i + 1]);
                for (int _j = dp[i] + 1; _j <= m; _j++) {
                    j = _j;
                    if (f2) j = m - _j + 1;
                    mn1 = min(mn1, arr[i][j]);
                    mx1 = max(mx1, arr[i][j]);
                }
            } f |= (mx1 - mn1 <= mid);
        }
    } return f;
}
void solve() {
    cin >> n >> m; dp[n + 1] = inf;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> arr[i][j]; mn = min(mn, arr[i][j]);
        }
    } int l = 1, r = inf, mid, ans = 0;
    while (l <= r) {
        mid = (l + r) / 2;
        if (check(mid)) {
            ans = mid; r = mid - 1;
        } else l = mid + 1;
    } cout << ans;
}
int32_t main() { 
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    
    dp[0] = inf;
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
        cout << '\n';
    }
    return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'void open_file(std::string)':
joioi.cpp:26:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:27:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 40 / 40